Check valve with flexible membrane

Abstract

The valve includes a body, a seat and a flexible membrane capable of being urged against the seat, while plugging passage ports of this seat. The passage ports have each an oblong shape and are arranged with their greatest dimensions oriented along radial directions of the seat. Applications: check valve or flow control valve for gaseous fluids, in particular in the automotive field.

Claims

1. A check valve with a flexible membrane, the check valve comprising: a hollow body; a seat disposed inside the hollow body transversely thereto, said seat being provided with passage ports; and the flexible membrane capable of being urged against the seat while plugging said passage ports thereof, or being spaced apart from said passage ports, said flexible membrane being maintained either by a center of said flexible membrane or by a periphery of said flexible membrane, wherein said passage ports have each an oblong shape such that each passage port has a greatest dimension and a smallest dimension, each passage port being disposed such that the greatest dimension is oriented along a respective radial direction of said seat, wherein each of said passage port is defined, on a face of said seat turned towards said flexible membrane by: two radial edges globally extending along respective radial directions, a proximal edge interconnecting said two radial edges, and a distal edge interconnecting said two radial edges, said distal edge extending radially farther than said proximal edge, and said distal edge is composed of one middle segment, and of two curvilinear segments, each curvilinear segment connecting said middle segment to one respective radial edge, said middle segment having, along a tangential direction, a length lower than half of a greatest width of said passage port.

2. The check valve according to claim 1, wherein said passage ports have an edge having a rounded profile, at least at an exit of said passage ports on the face of said seat turned towards said flexible membrane.

3. The check valve according to claim 1, wherein said middle segment is substantially rectilinear.

4. The check valve according to claim 1, wherein a ratio characterizing the oblong shape and having: as a numerator, a length of said passage port, measured according to a radial direction between said proximal edge and said middle segment, and as a denominator, a greatest width of said passage port is higher than 1.3.

5. The check valve according to claim 1, wherein a ratio having: as a numerator, a greatest width of said passage port, and as a denominator, a distance separating two consecutive passage ports, measured parallel to a tangential direction, is lower than 2.7.

6. The check valve according to claim 1, wherein said flexible membrane is maintained on a central pin carried by said seat, said passage ports being arranged in a radiating manner around said central pin.

7. A flow control check valve with a flexible membrane, the flow control check valve comprising: a hollow body; a seat disposed inside the hollow body transversely thereto, said seat being provided with passage ports; and the flexible membrane capable of being urged against the seat while plugging said passage ports thereof, or being spaced apart from said passage ports, said flexible membrane being maintained either by a center of said flexible membrane or by a periphery of said flexible membrane, wherein said passage ports have each an oblong shape such that each passage port has a greatest dimension and a smallest dimension, each passage port being disposed with the greatest dimension oriented along a respective radial direction of said seat, wherein each of said passage port is defined, on a face of said seat turned towards said flexible membrane by: two radial edges globally extending along respective radial directions, a proximal edge interconnecting said two radial edges, and a distal edge interconnecting said two radial edges, said distal edge extending radially farther than said proximal edge, and said distal edge is composed of one middle segment, and of two curvilinear segments, each curvilinear segment connecting said middle segment to one respective radial edge, said middle segment having, along a tangential direction, a length lower than half of a greatest width of said passage port.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) In any case, the invention will be better understood with the help of the following description, with reference to the accompanying schematic drawing representing, as examples, some embodiments of this check valve with a flexible membrane.

(2) FIG. 1 is a perspective and longitudinal section view of a check valve with a flexible membrane,

(3) FIG. 2 illustrates a seat of a check valve with conventional circular ports,

(4) FIG. 3 is a partial sectional view through the axis of a valve in accordance with the invention, in the closing position,

(5) FIG. 4 is a view similar to FIG. 3, representing the valve in the opening position,

(6) FIG. 5 shows the seat of the valve according to the invention, with its oblong-shaped ports,

(7) FIG. 5A is a front view of a portion of the seat of the valve of FIG. 5, on a larger scale,

(8) FIG. 6 is a sectional view through the axis of another valve in accordance with the invention, in the closing position,

(9) FIG. 7 is a view similar to FIG. 6, showing the valve in the opening position, and

(10) FIG. 8 illustrates an example of application of the check valve subject-matter of the invention.

DETAILED DESCRIPTION

(11) Referring to FIGS. 1, 3, 4, 6 and 7, a check valve, designated as a whole by the reference 1 and hereinafter simply called valve, comprises a hollow body composed of two joined portions 2 and 3, arranged along a same longitudinal axis A. The first portion 2 of the body is extended by an inlet end-piece 4 for a fluid, while the second portion 3 of this body is extended by an outlet end-piece 5 for the fluid.

(12) A seat 6, here integrated into the first portion 2 of the body, extends transversally to the longitudinal axis A. A flexible membrane 7, of a circular shape, is mounted inside the body, opposite to one face of the seat 6, the membrane 7 being here fastened by its center. In particular, as illustrated in FIGS. 1, 3 and 4, the membrane 7 may be maintained on a central pin 8, integral with the seat 6.

(13) The seat 6 is pierced with a plurality of passage ports 9, arranged all around the axis A and in particular the central pin 8. The ports 9 communicate with the internal channel 10 formed by the inlet end-piece 4.

(14) In the closing position of the valve 1, as illustrated in FIG. 3, a fluid pressure at the outlet end-piece 5 side (or a depression at the inlet end-piece 4 side) urges the membrane 7 against one face of the seat 6, so that this membrane 7 plugs all the ports 9, thus preventing any fluid backflow.

(15) In the opening position of the valve 1, as illustrated in FIG. 4, the membrane 7 is detached from the seat 6 and authorizes the fluid circulation, in a direction called passing (arrow F), from the inlet end-piece 4 toward the outlet end-piece 5 through the ports 9.

(16) As shown in FIG. 2, the passage ports 9 are conventionally of a circular shape, and few in number, typically five. These circular ports usually have sharp-ridged edges.

(17) According to the invention, and as represented in FIG. 5, the passage ports 9 have each an oblong shape. More particularly, the greatest dimension of each port 9 is oriented along a radial direction R of the seat 6. All of the ports 9 thus have a daisy arrangement, these ports 9 being for example eight in number and separated by regular angular intervals of 45.

(18) Each port 9 has rounded angles, in the plane of the seat 6. In addition, the edge 11 of each port 9, at the exit of that port on the face of the seat 6 turned toward the membrane 7, has a rounded profile, in a plane perpendicular to said face of the seat 6, as suggested by the small arrows a. Two diametrically opposed edges 11 are separated by a distance D11, represented in FIG. 5, which is here about 11 mm.

(19) In the embodiment according to FIGS. 3 to 5, the passage ports 9 have a radiating arrangement around the central pin 8, on which the membrane 7 is retained.

(20) As shown in FIG. 5A, each passage port 9 is defined, on the face of the seat 6 turned towards the membrane 7: by two radial edges 21 and 22 globally extending along respective radial directions R, separated by an angle of about 40 degrees, by one proximal edge 23 interconnecting the two radial edges 21 and 22, by one distal edge 24 interconnecting the two radial edges 21 and 22, the distal edge 24 extending farther from the other passage ports 9 than the proximal edge 23; the distal edge 24 corresponds to the edge 11.

(21) The distal edge 24 is composed of a middle segment 24.0, preferably substantially rectilinear, and two curvilinear segments 24.1 and 24.2. Each curvilinear segment 24.1 and 24.2 is here arc-shaped. The middle segment 24.0 is here rectilinear.

(22) Each curvilinear segment 24.1 or 24.2 connects the middle segment 24.0 to one respective radial edge 21 or 22. The middle segment 24.0 has, along a tangential direction T, a length L24.0 lower than half of the greatest width W9 of the passage port 9. In this case, the length L24.0 measures 0.9 mm and the greatest width W9 measures 2.35 mm. This length L24.0 and this greatest width W9 define a distal edge 24 relatively curved.

(23) The greatest width W9 of the passage port 9 is defined as the distance separating the two intersection points 24.21 and 24.22 between the curvilinear segments 24.1 and 24.2 and the radial edges 21 and 22.

(24) In the example of FIG. 5A, the length L9 of the passage port 9 is about 3.2 mm and the greatest width W9 of the passage port 9 between the intersection points 24.21 and 24.22, is about 2.35 mm.

(25) The ratio characterizing the oblong shape and having: as numerator, the length L9, measured according to a radial direction R between the proximal edge 23 and the middle segment 24.0, and as denominator, the greatest width W9

(26) is about 1.36, hence higher than 1.3. This ratio offers an important gain in the total passage section.

(27) Moreover, another ratio having: as numerator, the greatest width W9 of the passage port 9, and as denominator, the distance D9.9 separating two consecutive passage ports 9, measured parallel to a tangential direction T, and which is here about 0.9 mm,

(28) is about 2.6, hence lower than 2.7.

(29) This ratio allows guaranteeing a uniform support of the membrane while minimizing the risk of reducing the fluid passage section.

(30) FIGS. 6 and 7 represent, respectively in the closing position and in the opening position, another embodiment wherein the membrane 7 is maintained by its center thanks to a particular configuration of the second portion 3 of the body of the valve, without resort to a fastening central pin. In this case, the passage ports 9 are still oblong-shaped, but they have a radiating arrangement around the longitudinal axis A of the valve 1.

(31) In all its embodiments, the check valve 1 according to the invention, with its oblong-shaped passage ports 9, has a global passage section (in the opening position) at least equivalent to that of conventional circular ports according to FIG. 2, while offering a better support of the membrane 7, hence an improved sealing (in the closing position).

(32) Furthermore, the invention allows reducing the unit size of each port 9 relative to circular ports, which reduces the force exerted at the ports 9 in case of overpressure and thus improves the pressure resistance of the membrane 7 in the non-passing direction. The shape of the ports 9, associated to the rounding a of the edges 11 of these ports, contributes for a same membrane 7 to increasing the pressure resistance of that membrane, hence to its resistance against tearing, the gain in the pressure resistance could amount to several bars.

(33) FIG. 8 illustrates one possible application for check valves according to the invention. Two valves are here incorporated into an oil vapors recycling circuit 12 associated with the cylinder-head-cover in a turbocharged engine. A first valve 1a is inserted at the start of a circuit branch 12a terminating upstream of the turbocharger. A second valve 1b is inserted at the start of another circuit branch 12b which terminates downstream of the turbocharger, at the engine air intake. The arrows F indicate the passing direction of the two valves 1a and 1b. The second valve 1b must here resist the turbocharger pressure.

(34) It goes without saying that the invention is not limited to the sole embodiments of this check valve with flexible membrane which have been described above, as examples; it encompasses, on the contrary, all the alternative embodiments and applications respecting the same principle. It is in this way, in particular, that there would be no departure from the scope of the invention: by modifying the detail of shapes and the number of the ports arranged in the seat of the valve, by modifying and adapting the ratio between the global passage section resulting from said ports, and the supporting surface of the membrane, by achieving these ports in a seat of any type, integrated into a portion of the valve body or designed as a separate part, by applying the invention to a valve with a membrane fastened by any means, in its center or on its periphery, by reserving this valve for circuits of fluids of any kind: air or other gases, vapors, gases loaded with droplets for example of oil in the case of crankcase gases recycling circuit, and even liquid transfer circuits, in the automotive field or in other activity sectors.